What arguments did G. E. Moore make in Principia Ethica?

Published in 1903 by English philosopher G. E. Moore, Principia Ethica introduced the concept of the naturalistic fallacy and helped shape modern metaethics. In it, Moore argued that goodness is a simple, unanalyzable property that cannot be defined in terms of natural properties like pleasantness. The book also outlines a form of consequentialism and relies on ethical intuitionism through a technique called the method of isolation.

What we know

• G. E. Moore introduced the term naturalistic fallacy in his 1903 book Principia Ethica. [3]
• The naturalistic fallacy is the claim that it is possible to define good in terms of merely described entities, properties, or processes. [3]
• Thomas Baldwin argues that Principia Ethica relies on ethical intuitionism and a technique known as the method of isolation for extracting moral intuitions. [4] · medium confidence
• Principia Ethica and Ethics (1912) are G. E. Moore's only two books about ethics. [4]

Still open

• Scholars disagree on whether Moore's later work Ethics maintains the exact same version of consequentialism found in Principia Ethica or marks a shift away from it.

Where to go next

• how it workedWhat is the naturalistic fallacy?
• compared withHow does Ethics compare to Principia Ethica?
• whoWho was G. E. Moore?
• the bigger pictureWhat is analytic philosophy?
• how we knowHow does David Hume's is-ought problem relate to ethics?
• an unexpected connectionHow did a book on logic connect to Cambridge intellectual circles?G. E. Moore was a prominent member of the Cambridge Apostles society, an elite intellectual group closely tied to the university circles where analytic philosophy and foundational works like Principia Ethica and Principia Mathematica were discussed.

Sources

• [1]G. E. Moore (Wikidata Q295386) · CC0 1.0
• [2]G. E. Moore · CC BY-SA 4.0
• [3]Naturalistic fallacy · CC BY-SA 4.0
• [4]Ethics (Moore book) · CC BY-SA 4.0
• [5]Alfred North Whitehead · CC BY-SA 4.0